Anybody shoot the savage predator 10 in 6.5 creedmoor

[Shayne w]

Trying to work up a mule deer load with eld-x 143 gr. so far RL 17 40.4 gr shoots ok but I get different Readings from my chronograph. Yesterday my SD was 4.9 today it was 13.4 any suggestions

 

[MCgunner]

How many shots per shot string? 5? 10? The more shots, the more accurate your SD is gonna be, simple statistics. 10 is a minimum for a decent sample size. I usually shoot 10. Five shots can be more erratic.

 

[Shayne w]

I have been shooting 5 shot strings, it seems about three strings in groups best not cleaning between strings. Should I foul a few shots and let the barrel cool before recording load data?

 

[MCgunner]

If you've fired 3 five shot strings, you have a sample size of 15, good 'nuf. Just do your SD calculation on all shots fired. One problem, if they're shot on different days at different atmospheric conditions, it could affect the velocities.

I was mearly thinking of the statistical variance of a 5 shot string vs 10 or more shots. Just that the larger the sample size, the more consistent the variance and therefore the the more accurate standard deviation.

 

[Bull Nutria]

Wow MC, sounds like you are laying some AGGIE Statistics on these old boys! Way to go , I would have to dig out some moldy stat books to come up with that answer! Most folks probably don't know you went to Texas A&M!!
Bull (U L Lafayette and LSU grad)

 

[horsey300]

I have been shooting 5 shot strings, it seems about three strings in groups best not cleaning between strings. Should I foul a few shots and let the barrel cool before recording load data?

I can't speak for any one else but I do know others will agree, I ALWAYS shoot cold and dirty.

 

[Bull Nutria]

I have found that a shots from a clean cold bore are almost always not very repeatable. I usually fire 2 rounds to foul the bore. Then I shoot for groups when testing new loads. always let the barrel cool between groups. From what I have read current thinking with modern propellants and jacketed bullets one should not scrub the bore until accuracy falls off.

With new barrels scrubbing is recommended after firing, I have noticed that the more you shoot a new barrel often times accuracy improves then settles in.

I don't Claim to be an expert this is just what I do and seems to work ok.

Bull